diff options
Diffstat (limited to 'maximum_width_ramp.c')
-rw-r--r-- | maximum_width_ramp.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/maximum_width_ramp.c b/maximum_width_ramp.c new file mode 100644 index 0000000..284fc8f --- /dev/null +++ b/maximum_width_ramp.c @@ -0,0 +1,33 @@ +// 962. Maximum Width Ramp +#include "leetcode.h" + +/* + * a ramp in an integer array 'nums' is a pair '(i, j)' for which 'i < j' and + * 'nums[i] <= nums[j]'. the width of such ramp is 'j - i'. given an integer + * array 'nums', return the maximum width of a ramp in 'nums' if there is no + * ramp in 'nums', return 0 + */ + +int maxWidthRamp(int *nums, int numsSize) { + int ans = 0, idx = 0; + int *stack = (int *)malloc(numsSize * sizeof(int)); + for (int i = 0; i < numsSize; i++) { + if (!idx) + stack[idx++] = i; + else { + if (nums[i] <= nums[stack[idx - 1]]) + stack[idx++] = i; + } + } + for (int i = numsSize - 1; i >= 0; i--) + while (idx && nums[i] >= nums[stack[idx - 1]]) + ans = fmax(ans, i - stack[--idx]); + free(stack); + return ans; +} + +int main() { + int n1[] = {6, 0, 8, 2, 1, 5}, n2[] = {9, 8, 1, 0, 1, 9, 4, 0, 4, 1}; + printf("%d\n", maxWidthRamp(n1, ARRAY_SIZE(n1))); // expect: 4 + printf("%d\n", maxWidthRamp(n2, ARRAY_SIZE(n2))); // expect: 7 +} |